We have numbers 2136 and 3004. Let's start adding them together.

Step 1: We'll start by adding the digits 6 & 4 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 3 & 0 in column 2 and get 4.

Step 3: We'll start by adding the digits 1 & 0 in column 3 and get 1.

Step 4: We'll start by adding the digits 2 & 3 in column 4 and get 5.

So, 2136 + 3004 = 5140.

